/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/************************************************************************
 * kernel/signal/sig_kill.c
 *
 *   Copyright (C) 2007, 2009, 2011, 2013 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ************************************************************************/

/************************************************************************
 * Included Files
 ************************************************************************/

#include <tinyara/config.h>

#include <sys/types.h>
#include <sched.h>
#include <errno.h>
#include <debug.h>

#include "sched/sched.h"
#include "signal/signal.h"

/************************************************************************
 * Global Functions
 ************************************************************************/

/************************************************************************
 * Name: kill
 *
 * Description:
 *   The kill() system call can be used to send any signal to any task.
 *
 *   Limitation: Sending of signals to 'process groups' is not
 *   supported in TinyAra
 *
 * Parameters:
 *   pid - The id of the task to receive the signal.  The POSIX kill
 *     specification encodes process group information as zero and
 *     negative pid values.  Only positive, non-zero values of pid are
 *     supported by this implementation.
 *   signo - The signal number to send.  If signo is zero, no signal is
 *     sent, but all error checking is performed.
 *
 * Returned Value:
 *    On success (at least one signal was sent), zero is returned.  On
 *    error, -1 is returned, and errno is set appropriately:
 *
 *    EINVAL An invalid signal was specified.
 *    EPERM  The process does not have permission to send the
 *           signal to any of the target processes.
 *    ESRCH  The pid or process group does not exist.
 *    ENOSYS Do not support sending signals to process groups.
 *
 * Assumptions:
 *
 ************************************************************************/

int kill(pid_t pid, int signo)
{
#ifdef CONFIG_SCHED_HAVE_PARENT
	FAR struct tcb_s *rtcb = this_task();
#endif
	siginfo_t info;
	int ret;

	/* We do not support sending signals to process groups */

	if (pid <= 0) {
		ret = -ENOSYS;
		goto errout;
	}

	/* Make sure that the signal is valid */

	if (!GOOD_SIGNO(signo)) {
		ret = -EINVAL;
		goto errout;
	}

	/* Keep things stationary through the following */

	sched_lock();

	/* Create the siginfo structure */

	info.si_signo = signo;
	info.si_code = SI_USER;
	info.si_value.sival_ptr = NULL;
#ifdef CONFIG_SCHED_HAVE_PARENT
	info.si_pid = rtcb->pid;
	info.si_status = OK;
#endif

	/* Send the signal */

	ret = sig_dispatch(pid, &info);
	sched_unlock();

	if (ret < 0) {
		goto errout;
	}

	return OK;

errout:
	set_errno(-ret);
	return ERROR;
}
